Unionization increases income—not just for union workers but also for the entire middle class. A study conducted by the Center for American Progress Action Fund controlled for a host of other factors that also impact the strength of a state’s middle class—such as education, unemployment, and types of industries—and found that if unionization rates increased by 10 percentage points, the typical middle-class household, unionized or not, would earn $1,501 more each year. To put that figure in perspective, we found that a 10 percentage-point increase in the share of the population with a college degree would increase the average middle-class income by $1,664 a year.

In non-“right-to-work” states, workers are more likely to receive employer-provided health insurance and pensions. Workers in “right-to-work” states are significantly less likely to receive employer-provided health insurance and pensions. If benefits coverage in non-“right-to-work” states were lowered to the levels of states with these laws, 2 million fewer workers would receive health insurance and 3.8 million fewer workers would receive pensions nationwide.

Unions improve workplace policies and have beneficial policy effects more broadly. Unions advocate for broader worker protections needed for families to make human-capital investments—strong public education, social safety nets, minimum wages, paid leave, and even civil rights and efficient regulation.

Unions balance structures of power in the workplace, resulting in greater efficiency. Unions support high-productivity workplaces where information can flow from the bottom-up to improve business performance.

“Right-to-work” legislation fails to grow state economies. The laws have failed to increase employment growth in the 23 states that have adopted them, and in states more recently adopting “right-to-work” policies, employment growth and business relocations have reversed their previous expanding trends. In other words, the economic evidence shows that unions and union membership—not “right-to-work” laws—are what are conducive to broad economic growth.

Unions strengthen businesses and the economically vital middle class by giving workers a voice in both the workplace and our democracy. Unions do this by pushing for fair wages and good benefits, and also by encouraging citizens to advocate for middle-class-friendly policies such as a strong Social Security system and family-leave benefits.

Overall, union members earn 28 percent ($198) more per week than nonunion workers. Hispanic union members earn 50 percent ($258) more each week than nonunion Hispanics and African Americans earn 29 percent ($168) more each week if they are union members.

78 percent of private sector union workers have access to medical insurance through their jobs, compared with 51 percent of nonunion workers. And 77 percent of private sector union workers have access to a guaranteed (defined benefit) retirement plan through their jobs, compared with just 20 percent of nonunion workers.

Only 2.9 percent of union workers are uninsured, compared with 14.2 percent of nonunion workers.

Unions raise wages of unionized workers by roughly 20% and raise compensation, including both wages and benefits, by about 28%.

Unions reduce wage inequality because they raise wages more for low- and middle-wage workers than for higher-wage workers, more for blue-collar than for white-collar workers, and more for workers who do not have a college degree.

Strong unions set a pay standard that nonunion employers follow. For example, a high school graduate whose workplace is not unionized but whose industry is 25% unionized is paid 5% more than similar workers in less unionized industries.

The impact of unions on total nonunion wages is almost as large as the impact on total union wages.

The most sweeping advantage for unionized workers is in fringe benefits. Unionized workers are more likely than their nonunionized counterparts to receive paid leave, are approximately 18% to 28% more likely to have employer-provided health insurance, and are 23% to 54% more likely to be in employer-provided pension plans.

Unionized workers receive more generous health benefits than nonunionized workers. They also pay 18% lower health care deductibles and a smaller share of the costs for family coverage. In retirement, unionized workers are 24% more likely to be covered by health insurance paid for by their employer.

Unionized workers receive better pension plans. Not only are they more likely to have a guaranteed benefit in retirement, their employers contribute 28% more toward pensions.

Unionized workers receive 26% more vacation time and 14% more total paid leave (vacations and holidays).

Farron Cousins is the executive editor of The Trial Lawyer magazine and a contributing writer at DeSmogBlog.com. He is the co-host / guest host for Ring of Fire Radio. His writings have appeared on Alternet, Truthout, and The Huffington Post. Farron received his bachelor's degree in Political Science from the University of West Florida in 2005 and became a member of American MENSA in 2009. Follow him on Twitter @farronbalanced